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Biomedical subjects

K Adachi

Publications and source records attributed to K Adachi.

At least 415 records · Page 23Linked to original sources
PubMed1991

Polymerization and solubility of recombinant hemoglobins alpha 2 beta 2 (6Val) (Hb S) and alpha 2 beta 2(6Leu) (Hb Leu).

In an effort to clarify the role of amino acid hydrophobicity at the beta 6 position in sickling we have made recombinant hemoglobin tetramers containing beta 6 Val (Hb S) and beta 6 Leu (Hb Leu). Recombinant Hb S and Hb Leu had the same electrophoretic mobility, chromatographic behavior, and absorption spectrum. The deoxy form of both tetramers polymerized in high phosphate buffer (1.8 M) and exhibited distinct delay times prior to polymerization. The kinetics of polymerization for recombinant and native Hb S were similar, while recombinant Hb Leu polymerized more readily. The solubility of deoxy Hb Leu was less than deoxy Hb S, indicating that rapid polymerization and decreased solubility of deoxyhemoglobin is accelerated with increasing hydrophobicity at the beta 6 position.

Amino Acid Sequence↗
PubMed1991

Fluorometric assays for DNA topoisomerases and topoisomerase-targeted drugs: quantitation of catalytic activity and DNA cleavage.

We have introduced the novel application of a simple ethidium fluorescence assay, using covalently closed circular DNA, for the study of topoisomerase-targeted drugs. With the specificity of camptothecin for eukaryotic topoisomerases I and of VM26 for eukaryotic topoisomerases II, the two classes of enzymes can be assayed independently in crude extracts and during purification. These assays are fast, sensitive, and quantitative, have a large sample capacity, and eliminate the need for radioactive materials, filters, and agarose gels. We have demonstrated the use of this fluorescence assay to measure the inhibition of the relaxation and supercoiling activities of purified mammalian topoisomerases I and II and bacterial gyrase by nonintercalating drugs. Similarly, the production of drug-induced topoisomerase-mediated cleavable complexes was readily quantitated with both nonintercalating and intercalating drugs. When inhibition and cleavage with VM-26 were measured concurrently as a function of topoisomerase II concentration, a clear inverse relationship between topoisomerase II inhibition and cleavable complex production was observed. When the physiologically relevant salt K+L-glutamate- was used, quantitative relaxation by topoisomerase II was observed up to twice the salt concentration obtained with KCl. The enantiomer K+D-glutamate- gave exactly the same results, indicating that the enhancing role of glutamate- is non-stereospecific.

Amsacrine↗
PubMed1991

[The hemodynamics during hemodilution and its influence on the liver functions after hepatectomy for hepatocellular carcinoma with liver cirrhosis].

The hemodynamics during hemodilution occurred after hepatectomy for hepatocellular carcinoma with liver cirrhosis and its influences on the liver functions were studied. The hematocrit value gradually decreased about 10% until the 4th postoperative day owing to hemodilution after hepatectomy. While anemia progressed, cardiac index inversely increased. Under such a condition, oxygen consumption was maintained so that acidosis did not develop. Arterial blood ketone body ratio was also kept within a normal range except for a case whose hematocrit value decreased to 17.1%. Although the escaped hepatic enzymes such as GOT and GPT increased in the serum after hepatectomy, hemodilution was not responsible for their increase. While total bilirubin increased in the severe hemodiluted group, the increase was not due to hemodilution but caused by blood transfusion. The protein synthesis of the liver measured by rapid turnover protein levels in plasma was depressed after surgery, and this depression prolonged to the 14th postoperative day in the group whose hematocrit value decreased below 20%. These results suggest that it is better to keep hemodynamics without blood transfusion unless the hematocrit value decrease below 20%, and also better to maintain the hematocrit above 20% for liver regeneration after hepatectomy.

Adult↗
PubMed1991

[Cardiac mast cells in myocardial diseases].

Mast cells play a role in inflammation and immunological reactions. Cardiac mast cells with their granules are demonstrated easily by toluidine blue staining. We evaluated cardiac mast cells in endomyocardial biopsy specimens in patients with acute myocarditis (n = 17), idiopathic dilated cardiomyopathy (n = 17), idiopathic hypertrophic cardiomyopathy (n = 17) and control subjects (n = 12). Cardiac mast cells increase to an extreme degree in patients with acute myocarditis (2.4 counts/mm2) and increase relatively in patients with idiopathic dilated cardiomyopathy (1.4 counts/mm2). Patients with idiopathic hypertrophic cardiomyopathy (0.4 counts/mm2) were similar to control subjects (0.5 counts/mm2). Cardiac mast cells increased in accord with the severity of cellular infiltration and of interstitial fibrosis except for some cases with very severe fibrosis. In the acute myocarditis group, cardiac mast cells were well demonstrated in the early stage of the illness. But degranulations of mast cells did not give us any significant information in this study. Evaluation of cardiac mast cells will provide us with a new aspect in studying primary myocardial diseases.

Adolescent↗
PubMed1991

[Zinc concentration in the central nervous system in a case of multiple sclerosis--comparison with other neurological diseases].

The possible role of trace elements in a pathogenesis of central nervous system (CNS) on degenerative and demyelinating diseases has been suggested. Simultaneous measurements of Zinc (Zn) and iron (Fe) concentration in CNS were undertaken by neutron activation analysis in CNS tissues: a patient with multiple sclerosis (MS), five patients with amyotrophic lateral sclerosis (ALS), five with spinocerebellar degeneration (SCD), and five with cerebral infarction (CVD) in non-invasive area of CNS as control. Although Zn and Fe concentration were present in white matter and gray matter of CNS in each disease, 1) Zn concentration showed no special pattern in gray matter among four diseases, but decreased more in white matter of MS and ALS than that of CVD (p less than 0.05); 2) Fe concentration in gray matter of SCD increased more than that in CVD (p less than 0.05), but Fe concentration in white matter of CVD was increased more than that of ALS (p less than 0.05); 3) Fe concentration of CNS in a patient with MS was not notable except for high Fe concentration in caudate nucleus and globus pallidus. The demyelinated pathological area in CNS of MS showed a decrease in Zn level but no change in Fe level. These results indicate that low Zn concentration in CNS tissues of MS seemed to be responsible for CNS demyelination, but not for undernutrition due to poor conditions of a patient with MS. It seems that Zn might be one pathogenetic factor of MS, but the action of Fe in MS can not be ruled out.

Adult↗
PubMed1991

[Aluminum deposition in the central nervous system tissues of patients with Parkinson's disease].

Aluminum (Al) concentration in the 26 anatomic central nervous system (CNS) regions, liver, kidney, spleen and heart of our patients with Parkinson's disease, and five neurologically normal controls was measured by a non-destructive neutron activation analysis (NAA), in order to clarify the implication of Al on pathogenesis of Parkinson's disease. Al concentration in substantia nigra, caudate nucleus and globus pallidus increased in patients with Parkinson's disease more than that in controls (p less than 0.05). There was a significant difference in Al concentration of gray matter and basal ganglia in Parkinson's disease, compared with those of controls (p less than 0.01). It is likely that high Al deposition in pathological foci responsible for Parkinson's disease might be implicated in the pathogenesis of Parkinson's disease.

Aged↗
PubMed1991

TNF-driven inflammation during mouse liver regeneration after partial hepatectomy and its role in growth regulation of liver.

To determine the role of TNF-driven inflammation in self-regulation of cell growth and differentiation, mouse liver regeneration after partial hepatectomy was examined for TNF-driven inflammation. Hepatectomy provoked priming state for TNF production in both whole body and liver on day 3 when the peak mitotic response occurred. Histochemical studies of liver also showed an inflammatory symptom; hepatocellular necrotic foci appeared by 6 hours after hepatectomy. TNF itself was secreted spontaneously in liver transiently on day 1 to 2 after hepatectomy just before the proliferation of hepatocytes. Dexamethasone reduced both TNF secretion and hepatocyte proliferation after hepatectomy. Recombinant murine TNF stimulated the in vitro proliferation of hepatocytes. These findings indicate that hepatectomy induces short-term secretion of TNF in liver and TNF-driven inflammation has an important role in liver regeneration, at least in part by the direct stimulation of hepatocyte proliferation.

Animals↗
PubMed1991

Isolation and characterization of zinc coproporphyrin I: a major fluorescent component in meconium.

We isolated a substance from an organic extract of meconium (in neutral pH) that exhibited a porphyrin-like fluorescence peak at 580 nm on excitation at 405 nm and deduced its structure. Spectrometric data suggest that the substance is not free coproporphyrin I or free coproporphyrin III, but is a chelate of coproporphyrin I with Zn2+. We also detected a chelate of coproporphyrin III with Zn2+ by HPLC. These substances may be useful as new indicators of the presence of meconium.

Amniotic Fluid↗
PubMed1991

[Quantitative analysis of myocardial fibrosis in myocardial biopsies--a comparison between computer analysis and point counting method].

To select an appropriate method to analyze quantitatively myocardial fibrosis in myocardial biopsies, two methods, the computer analysis and the point-counting method observed at magnifications of x200 and x400, were compared. Our targeted points of examination were the accuracy and reproducibility of these methods. Twenty patients (10 with dilated cardiomyopathy and 10 with hypertrophic cardiomyopathy) were randomly selected, and the percent area of myocardial fibrosis in myocardial biopsies obtained from the right ventricular septum was measured by both the computer analysis and the point-counting method. Two observers measured the same area twice on the different days, independently. In the area of analysis, the endocardium was excluded to avoid the observer's bias. By comparing the data obtained from two observers, it was shown that the point-counting method tended to give a larger mean value and standard deviation than the computer analysis method, but that the latter indicated better reproducibility than the former. Our result showed that the degree of myocardial fibrosis varied according to methods of analysis and observer's experiences. It is recommended that the comparison of myocardial fibrosis should be made only when the methods of analysis of fibrosis are identical.

Cardiomyopathy, Dilated↗
PubMed1991

High aluminum deposition in the central nervous system of patients with amyotrophic lateral sclerosis from the Kii Peninsula, Japan: two case reports.

We report two cases of amyotrophic lateral sclerosis (ALS), in which metal analysis revealed markedly higher aluminum concentration in the central nervous system (CNS) as well as higher calcium and lower magnesium concentration and higher Ca/Mg ratios compared with controls. Case 1 was a 55-year-old housewife and total duration of illness was 2 years and 2 mon from onset of clinical symptom. Case 2 was a 80-year-old woman and total duration of illness was 10 mon. Results showed that neither were exposed to toxic environments nor any neurologic disease in the past history. Postmortem examination disclosed motor neuron death and degeneration of pyramidal tracts. The significance of metal metabolism in pathogenesis of amyotrophic lateral sclerosis is discussed.

Aged↗
PubMed1990

Differences in phosphatidate hydrolytic activity of human alkaline phosphatase isozymes.

Hydrolytic activities of human alkaline phosphatase isozymes were investigated using phosphatidases with various fatty acyl chains (egg phosphatidate and dioleoyl, distearoyl, dipalmitoyl, dimyristoyl and dilauroyl phosphatidates). In the presence of sodium deoxycholate, purified human placental and intestinal alkaline phosphatases hydrolyzed all the phosphatidates examined. The hydrolytic activity was maximal in the presence of 10 g/l sodium deoxycholate. Of the phosphatidates, dilauroyl phosphatidate was the best substrate. Using the same unit of the enzyme, the phosphatidate hydrolytic activity of placental alkaline phosphatase was 2- to 3-times higher than that of the intestinal enzyme. In contrast, liver alkaline phosphatase did not hydrolyze phosphatidates with long fatty acyl chains (C16-18) even in the presence of sodium deoxycholate. The liver enzyme hydrolyzed dimyristoyl and dilauroyl phosphatidates very slowly. These results show that the phosphatidates with long fatty acyl chains were useful to differentiate placental and intestinal alkaline phosphatases from the liver enzyme, and suggest that the former enzymes play a different physiological role from the liver enzyme.

Alkaline Phosphatase↗
PubMed1990

Orientation of the carboxyl terminus of the transposon Tn10-encoded tetracycline resistance protein in Escherichia coli.

A site-directed antibody was generated against a synthetic polypeptide corresponding to the 14 amino acid residues of the carboxyl terminus of the Tn10 TetA protein. The antibody reacted preferentially with inside-out vesicles, rather than right-side-out vesicles, prepared from Escherichia coli cells harboring transposon Tn10. When inside-out vesicles were treated with trypsin, the TetA protein was completely digested in the vicinity of the carboxyl terminus, as judged on immunoblot analysis using the antibody. In contrast, when right-side-out vesicles were treated with trypsin, the TetA protein was hardly digested. These results indicate that the carboxyl terminus of TetA is exposed to the cytoplasmic side of the membrane.

Amino Acid Sequence↗
PubMed1990

Characterization of two types of fetal hemoglobin: alpha 2G gamma 2 and alpha 2A gamma 2.

The effect of differences in G gamma and A gamma fractions of fetal hemoglobin (HbF) on the kinetics of polymerization of HbS-HbF mixtures was studied. We also examined their effect on oxygen affinity, surface hydrophobicity, mechanical stability, and solubility of HbF. Differences in G gamma:A gamma ratio did not affect the polymerization of mixtures of HbF and HbS, suggesting that the inhibitory effect of HbF on the polymerization of HbS is independent of the G gamma:A gamma ratio of HbF and is totally dependent on the fraction of HbF in the mixture. The oxygen equilibrium curve of HbF was not affected by differences in the ratios of G gamma and A gamma in HbF. In contrast, surface hydrophobicity, mechanical stability, and solubility of HbF were affected by differences in the G gamma:A gamma ratio. The higher the G gamma:A gamma ratio, the smaller the elution volume on a TSK Gel SW hydrophobic column in high phosphate buffer. The mechanical stability of HbF was also dependent on the ratio of G gamma:A gamma; stability was greater at higher fractions of A gamma. Differences in the G gamma:A gamma ratio also affected solubility of HbF: HbF containing the higher fraction of G gamma was the more soluble. These data indicate that although alanine at the 136th position of the gamma chains has a stronger surface hydrophobicity than does glycine, this difference does not affect either the polymerization of HbS or the oxygen affinity of HbF.

Alanine↗
PubMed1990

In vitro properties of human melanoma cells metastatic in nude mice.

We have developed a human melanoma metastasis model in nude mice. In this model, a human variant cell line (451-LU) was obtained that spontaneously metastasized in nude mice. This variant cell line was selected from the lung of a nude mouse after several in vivo passages of human melanoma WM164 cells previously isolated from a melanoma metastasis of a patient. The WM164 cells were not competent for metastasis in nude mice prior to this selection. We compared the phenotypes of the parental nonmetastatic cell line and the metastatic variant with respect to growth at clonal seeding densities in protein-free medium (growth factor independence), in vitro invasion through reconstructed basement membranes, secretion of proteolytic enzymes, expression of tumor-associated antigens, and chromosomal abnormalities. Metastatic 451-LU cells showed significantly increased growth factor independence when grown at clonal seeding densities as compared to the parental cells. In in vitro chemoinvasion assays, metastatic 451-LU cells were significantly more invasive than the parental cells. The metastatic variant secreted collagenase and tissue type plasminogen activator at levels 10- and 3-fold higher than the parental WM164 cells, respectively. Polyclonal antibodies to tissue type plasminogen activator significantly inhibited invasion through reconstructed basement membranes. In metastatic 451-LU cells, expression of nerve growth factor receptor was elevated, both at the protein and transcriptional level. Metastatic cells were aneuploid with a mode of 97 chromosomes, whereas the parental nonmetastatic cells had a mode of 52 chromosomes. Our studies suggest that metastatic melanoma cell variants selected in vivo show increased independence of exogenous growth factors when grown at clonal cell densities, enhanced invasiveness in vitro, greater secretion of proteolytic enzymes, and increased chromosome mode as compared to the nonmetastatic parental cells. The data further suggest that melanoma cells isolated from metastatic lesions and maintained in vitro have an unstable invasive phenotype but that metastatic variant cells can readily be selected.

Animals↗